Generator apparatus.



0. M. LEI OH.

GENERATOR APPARATUS.

APPLICATION FILED JUNE 19, 1908.

Patented July 12, 1910.

INVENTOI? Oscq/FM LE/ch' By M A TTOR'NEY W/ TNESSES MWQ UNITED STATES PATENT OFFICE.

OSCAR M. LEIGH, OF GENOA, ILLINOIS, ASSIGNOR 'IO CRAGRAFT-LEICH ELECTRIC 00.,

OF GENOA, ILLINOIS.

GENERATOR APPARATUS.

Application filed June 19, 1908.

To all whom it may concern:

Be it known that I, OSCAR M. LEIGH, a citizen of the United. States, residing at Genoa, in the county of Dekalb and State of Illinois, have invented a certain new and useful Improvement in Generator Apparatus, of which'the following is a full, clear, concise, and exact description, reference being had to the accompanying drawings, forming a part of the specification.

My invention relates to generator apparatus, and has for its object the provision of an improved generator, applicable more par ticularly for use in telephone appliances and for gas engine work.

I will describe my invention more in detail by reference to the accompanying drawing illustrating one embodiment thereof, in which Figure 1 shows a conventional type of generator to which my invention is applicable. Fig. 2 shows a partial horizontal sectional view of said generator along the line of the axis of the armature. Fig. 3 is a sectional view on lines 6-4) of Fig. 2, and Fig. 4 is a sectional view on lines aa of Fig. 2.

Like characters of reference indicate like parts throughout the different figures.

The generator shown in the figures comprises permanent magnets 1-1, suitably mounted upon the pole pieces 22. The pole pieces have end plates 33, which provide suitable bearings for the armature 4L, and at the same time provide suitable bearings for the counter shaft 5, which is operated by means of a handle 6, through the interposition of gears 7 and 8. The armature 4, is wound with many turns of fine wire 9, one of which is brought to the terminal 10, and the other terminal of which is preferably conduct-ively associated with the frame or pole pieces 2. A circuit is thus established from the spring 10 to the frame of the machine.

In manufacturing generators of this type, which at the present time find their greatest use in telephone apparatus, and for gas engine Work, it is the custom to construct the armature 4L of non-laminated material. In other words to make it of one solid casting. Both ends of the armature 4 are provided with over-hanging extensions 11-11, which protect the wire and to which suitable cover plates 12l2, are secured. The cover plates 1212 are each provided with a shaft exten- Speeification of Letters Patent.

Patented July 12, 1910.

Serial No. 439,309.

sion, which shaft finds its hearings in the end plates 33. By virtue of this construction it will be seen that it is not necessary to have the shaft ends extend through the solid port-ion of the armature 4-. A great dilliculty experienced in this type of armature is that due to the generation of eddy or Foucault currents, which have a great tendency to retard the rotation of the armature. This is due to the closed pat-h provided by the armature to such currents. To avoid the effect of these excessive Foucault currents I so construct the armature that the closed circuit path thus provided is broken, and therefore these currents do not have the same facility for a complete circuit, and they are, therefore, not generated in objectionable amount. This is accomplished by virtue of my improved construction, which I will now describe.

The general cross section of the armature 4, is shown more in detail in Fig. 3. I take this armature 4t and saw slots 1313 transversely across the axis of the armature, the cross sectional outline of which slots is more clearly shown in Fig. 4. It will thus be seen that the eddy currents which have a tendency to flow in a closed circuit longitudinally of the armature, meet obstructions in their paths due to these air recesses 13, and the resistance provided in this path in oppoition to them is so great that they do not flow except very close to the axis of the armature, at which point they do little or no damage. These higher resistance obstructions to the path of the eddy currents in my improved device take the form of transverse slots 13, as above specified. The etliciency obtained from a machine of this kind is remarkable more especially when starting the machine, or when attempting to operate on open circuit or no load.

While I have herein shown and particularly described the preferred embodiment of my invention, I do not wish to limit myself to the precise construction and arrangement as herein set forth, but

Having thus set forth its most salient features what I claim as new and desire to secure by Letters Patent is A magneto generator comprising perinanent magnets, solid pole pieces for said permanent magnets, a solid metallic armature of magnetic material for operation adja cent to said pole pieces, non-magnetic me tallic end plates provided with shaft eXten- I to the flow of eddy currents to thereby desions secured to overhanging ends of said l crease the eifort necessary in the rotation of armature, said shaft extensions not extendsaid armature, a slot being located close to ing through the armature proper, and a plueach of the ends of said armature.

5 rality of thin transverse slots for subdivid- In witness whereof, I hereunto subscribe 15 ing each one of the two opposite halves of my name this 31st day of March, 1908. said armature into a plurality of substan- OSCAR M. LEIGH. tially independent magnetic portions, pro- Witnesses: vided in each of the opposite halves of said MAX ZABEL,

10 armature to increase the resistance offered 0. M. NENNIEL. 

